The invention concerns an aortic balloon occlusion cannula for the occlusion of the ascending aorta during cardiac surgery.
An arteriosclerotically altered ascending aorta represents a problem in the field of cardiac surgery. It occurs in almost all patients who suffer from calcification of the coronary vessels or, to different degrees, in patients with valvular diseases. It is necessary to insert an aortic cannula into the ascending aorta in order to connect for instance a patient, who undergoes a bypass operation, to the extra corporal circulation (heart-lung machine). The blood circulation is separated from the heart by clamping the ascending aorta towards the heart that is proximal, with a metal clamp, which is attached at right angles. There is, however, the danger of a detachment of particles or plaques from the wall of the ascending aorta which are transported by the blood flow especially into the blood vessels of the head and therefore into the brain. This leads to embolies, which appear clinically often in form of neurological failures (cerebral infarction).
An aortic balloon occlusion cannula is known from the DE 19 15 933 A1. It is used to avoid the risks going along with aortic clamping at right angles during the extracorporeal circulation that is applied during cardiac surgeries. It includes an occlusion cannula that can be inserted into a catheter. Its lumen is connected on both sides to a dilatable balloon, which allows closing the ascending aorta from the inside by means of a balloon occlusion during the ischemic time without an aortic clamping at right angles. A similar aortic occlusion cannula has also been described in the U.S. Pat. No. 5,334,142, especially in connection with cardiopulmonary resuscitation. Further embodiments of occlusion cannulae having two dilatable balloons are disclosed in U.S. Pat. No. 5,458,574 and in EP 1 086 717 A1.
These balloon cannulae, however, do not solve the problems of other dangers, which can also lead to a calcified embolie as a result of an arteriosclerotic ascending aorta.
In order to be able to suture the vein bypass to the aorta during a bypass surgery, the aorta has to be clamped with a metal clamp over a certain length in the area of the suture. There is a considerable risk of embolie connected with this therapy. In order to provoke a cardiac arrest, it is also necessary to infuse a cardioplegic substance into the ascending aorta. It is also possible that plaques are separated if a cardioplegic conduction is inserted especially for this purpose into the ascending aorta.